Sulfophenethylsiloxane or sulfonaphthethylsiloxane and processes for their production are known. The U.S. Pat. No. 2,968,643 describes a reaction of chlorosulfonic acid and a phenyltrichlorosilane to form an intermediate followed by hydrolysis of this intermediate. However, an excess of chlorsulfonic acid is used which has to be separated. The U.S. Pat. No. 4,575,559 discloses a process for the production of sulfophenethylsiloxanes in the presence or absence of solvent. The solventless process in a stirred vessel is technically very difficult because the reaction mixture becomes solid. For this reason most examples use solvents, which must subsequently be removed.
The U.S. Pat No. 5,091,548 discloses a solventless process for the production of sulfophenethylsiloxanes or sulfonaphthylethylsiloxanes, wherein the reaction takes place in small droplets or in a thin film to avoid the handling of the solid intermediate in bulk form.
Object of the present invention was to provide a process for preparing sulfophenylalkylsiloxanes or sulfonaphthylalkylsiloxane which overcomes the problems of handling the solid intermediate and which avoids the use of a solvent. Another object was to provide the phenylalkylsiloxanes or sulfonaphthylalkyl-siloxanes in form of a powder.